The National Cooling System designed RO Water Chilling unit is a machine that removes heat from the Water via Vapor Compression Refrigeration System. It consists of four major parts- an Evaporator, a Condenser, a Compressor, and a metering device. The primary function of a water chilling unit is to remove heat from the water, which it does by sucking up the heat using refrigerant. This refrigerant is a chemical having heat absorbent properties.